212 RUBIACK^. (madder FAMILY.) 



axillary clusters ; corolla nearly wheel-shaped (white), much shorter than the 

 calyx. ((). uniflura, L. Ikdyotis glouierata, EU.) — Wet places, S. New York 

 to Virginia near the coast, aud southward. 



7. HOUSTONIA, L. IIoustonia. 



Calyx 4-lol)ed, persistent; the lobes in fruit distant. Corolla salver-form or 

 funnel-form, usually much longer than the calyx-lobes, 4-lobed, the lobes valvate 

 in the bud. Stamens 4 : anthers linear or oblong. Style 1 : stigmas 2. Ovary 

 2-cellcd. Pod top-shaped, globular, or didymous, thin, its summit or upper 

 half free from and projecting beyond the tube of the calyx, loculicidal across the 

 top. Seeds rather few (4-20 in each cell), peltate and saucer-shajjed or globu- 

 lar-tiiimble-shaped. pitted. — Small herbs, with short entire stipules connecting 

 the petioles or narrowed bases of the leaves, and cymosc or solitary and pedun- 

 cled flowers. These are dimorphous, in some individuals with the anthers borne 

 high up on the tube of the cofolla and projecting from its throat, while the style 

 is short and the stigma therefore included : in the other sort the anthers are low 

 down in the corolla and the style long, the stigmas therefore protruding ; — an 

 arrangement for cross-fertilization. (Named for Dr. Wm. Houston, an English 

 botanist who collected in Central America.) The genus, formerly merged in 

 Oldenlandia, merits S-estoration. 



* Erect, mosf/i/ perennial herbs (G'-20' hir/h), tvith siern-leaves sessile, and flowers 



in terminal small cymes or clusters: corolla funnel-form, purplish, often hairy in- 

 side: seeds meniscoiddl , ivith a ridije acj-oss the hollowed inner face. 



1. H. purpurea, L. Pubescent or smooth (8'- 1 5' high); leaves varyiu;/ 

 from roundish-ovate to lunceolote, 3 - 5-ribbed ; calyx-lobes longer than the Imlf 

 free globular pod. (IIoustonia purpurea, Z. H. varians, ^l/(t7ij-. Oldenlandia 

 purpurea, ed. 2.) — Woodlands, W. Pennsylvania to Illinois and southward. 

 May- July. — Varying wonderfully, as into : — 



Var. longif61ia. Leaves varying from oblong-lanceolate to linear, nar- 

 rowed at the base, 1-ribbed ; calyx-lobes scarcely as long as the pod ; stems 5'- 

 12' high. ( IIoustonia longifolia, Willd.) — Maine to Wisconsin and southward. 

 — A narrow-leaved, slender form is 11. tenuifolia, Nutt. 



Var. ciliolata. More tufied stems .3'-G' high; root-leaves in rosettes, 

 thickish and ciiiate ; calyx-lobes about as long as the pod. (Houstonia ciliolata, 

 Torr.) — Along the Great Lakes and rivers, from N. New York to Wisconsin. 



2. H. angustif61ia, Michx. Stems tufted from a hard or woody root; 

 leaves narrowly linear, acute. 1-ribbed, many of them fascicled; flowers crowded, 

 short-pedicelled ; lobes of the corolla densely bearded inside ; pod oboroid, acute at 

 the l)a.<ip, only its summit free from the calyx, opening first across the top, at length 

 through the partition. (Oldenlandia angustifolia, ed. 2. Hcdyotis stcnophylla, 

 Torr. ^- Gray.) — Plains and banks, from Illinois southward. June -Aug. 



* * Small and delicate, chiefly annuals or biennials, vernal-flowerinf] : ptdunchs \-flow- 



ered : corolla sed vi-r-furm : upper half of the broad and somewhat '2-lobed pod free : 

 seeds (/lobular, ivith a very deep round cavity occupying the inner face. 



3. H. minima, Beck. Scabrous; stems at length much branched and 

 spreading (l'-4' high); lowest leaves ovate or spatulate, the upper oblong or 



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